<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>CSS引入方式</title>
  <style> 
  div {
    color: red;
    font-size: 20px;
  }
  </style>

</head>

<body>
  
  <div>样式</div>

</body>
</html>